From: Tom Lane <tgl@sss.pgh.pa.us>
To: Yun Li <liyunjuanyong@gmail.com>
cc: pgsql-hackers@lists.postgresql.org
Subject: Re: Feature improvement: can we add queryId for
 pg_catalog.pg_stat_activity view?
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Comments: In-reply-to Yun Li <liyunjuanyong@gmail.com>
	message dated "Fri, 15 Mar 2019 14:54:19 -0700"
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Date: Fri, 15 Mar 2019 21:50:08 -0400
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Yun Li <liyunjuanyong@gmail.com> writes:
> Do you think if we can add queryId into the pg_stat_get_activity function
> and ultimatly expose it in the view? It would be easier to track "similar"
> query's performance over time easier.

No, we're not likely to do that, because it would mean (1) baking one
single definition of "query ID" into the core system and (2) paying
the cost to calculate that ID all the time.

pg_stat_statements has a notion of query ID, but that notion might be
quite inappropriate for other usages, which is why it's an extension
and not core.

			regards, tom lane